The evolution of freeway management systems has demonstrated that the quality of information that can be disseminated to the traveller can be significantly improved through the integration of a broad range of sensors, the increase in system computer processor power, and the inclusion of an improved mix of traveller information devices. Farradyne Systems, Inc has designed, developed, and deployed several such systems, and by means of a description of three of them, the author will demonstrate the nature and magnitude of this evolution, as well as some indications of potential future enhancements. The three projects that will be discussed are the Variable Speed Limit System in Albuquerque, followed by the Fog Albuquerque, followed by the Fog Warning System in Tennessee, and completed by the Travel Aid Project in the State of Washington. Each project uses both weather sensors and vehicle detectors, deployed in an array that supplies realtime information to roadside computers. The evolution of the systems demonstrates increasing complexity in terms of communications links, processing logic, and the means through which traveller information is provided. (A)
Samenvatting